Automatic blow-off for steam driers



May 12, 1942. o. w. CARRICK ETAL v 28 I AUTOMATIC BLOW-OFF FOR STEAM DRIERS Filed Sept. 1, 19 39 2 Sheets-Sheet 1 May 12, 1942. o. .w. CARRICK ET AL 2,282,540

AUTOMATIC snow-0F? FOR STEAM mums Filed Sept. 1, 1959' 2 Sheets-Sheet 2 I9 Wand Gar/(ck.

Patented May 12, 1942 UNITED ,STATES PATIENTQOFFICE AUTOMATICBLOW-OFF I v 1 *DRIERS' Oland W; Garrick and Lewis 0. Gunderson, Chi-v 'cago, Ill., assignors to Electro-CheinicalEnginearing Corporation, Chicago, Ill.,; a .corporation of Delaware FOR STEAM Application September 1, 1939, Serial No. 292,984

4 Claims. (01. 122-492) This invention relates .to the removal from a boiler, of water that is separated from steam in the'boilerby means of steam driers particularly of the tangential or centrifugal type.-

More specifically the: invention relates to the '5 glasses in the steam dome cover on an operating separation from steam, of water entrained therelocomotive have proved to us that, even under norin, and the automatic removal of. the separated mal operating conditions, the conventional tanwater from a steam boiler. gential drier is ineffective in separating moisture While the invention will hereinafter be deentrained as fine particles with the steam bescribed in connection with locomotive boilers, it 10 cause the centrifugal velocity within the drier is should be understood that the invention is adapt insufiicient to separate such finely divided pared for use on any type of steam boiler. ticles. This is due to the fact that the sepa- According to this invention a'tangential steam rated water must drain by gravity only back into drier'is mounted as usual in the steam dome of theboiler. Even this gravity drainage is inhiba locomotive boiler on the steam outlet pipe of 5 ited due to the reduction in pressure inside of the boiler. The tangential drier includes an the drier bowl. open-topped bowl receiving steam from the steam -We have found that the drains from steam space of the boiler. A plurality of vanes are driers in boilers shouldnot drain back into the mounted in the bowl so that the entering steam boilers forefficient separation'of, entrained water is givena whirling motion as it passes downward- 20 out of the steamg "According to this invention,

ly into the bowl. Entrained water is thus thrown out of the steam by centrifugal force and drains to the bottom. of the bowl. The dried steam enters the outlet pipe above. the bottom of the Heretofor'e the separated water has merely been drained from the bottom of the bowl back into the boiler through drain. nozzles. These drain nozzles must necessarily open into the steam space. of the boiler and when foamis developed in the steam space the mouths actually be submerged in foam.

We have found that during operation of the boiler, the interior of the drier bowl isrunder less pressurethan the pressure in the surrounding steam space of the boiler. This is probably due to the frictional resistance on the steam and entrained water caused by the tangential vanes in the mouth of thedrier bowl. There is thus a suction action at the ends of the drain nozzles and assoon as the nozzles are submerged in foam, this foam is sucked into the drier and is immediately entrained with the steam entering of thenozzles may the steam outlet pipe from the boiler.

Thus, instead of producing adrier steamwhen the foam level in the boiler reaches the endof the drain nozzle from the tangential drier, actu ally the moisture content of the steam is very much increased and 'the steam is contaminated not only with moisture but with a concentration of adsorbed foreign gritty material'such as alkaline earth carbonates and hydrates from the foam. This foreign material may subsequently be deposited in the front end throttles and in'the superheater tubes of the locomotive,'caus'ing'partial or complete stoppage of the tubes and subsequent :burning out :by therhot gases from the firebox.

-.Furthermore,. observations through sight therefore, the. conventional drain nozzles on steam driers .are replaced with larger diameter pipes extendin noutside of. the boiler to a blowoifvalve This; blow -off valve is automatically actuated by meansof an electrodewhich can be interposed in the drain line or inthe drier bowl. The electrode is insulated from the boiler and,,as soon as separated water in the drain line or in the bottom of the drierbowl contacts the electrode,' an electric jcircuit is closed for effecting 'an' opening oftheblow oif valve. This blow off valve willfremjain open only as long' as water c 'nitw t e.e i if -'In this manner the s'eparated water from the steam drier discharges, to the atmosphere and the boil'e'ii pres'sure is 'efiective'to provide a rapid discharge; Since the separated water itself con-' trols the operation of the blow-off valve, the device is entirely automatic in operation.

There'can be no suction of foam into the drier bowl-sinc'eth'e drainlines from the drier do not communicate'with theboiler. Furthermore, the finely divided moisture particles in the steam are moreefiiciently separated from the steam by the drier because-the drainage of the separated water from the drier bowl does not depend upon grav ityalonebutiactuallyiseffected by the pressure, existing. in theboileni'fThis speeds up the centrifugal velocity of-the 'ste'am entering the drier and effects a better: separation of moisture from the steam than; was heretofore possible;

.. :A;featur.e.of-: the invention includes the provision: of -a. second.electrode in the steam space 1ofythe boiler for'effectinga blowing-off of the .lower portion of the boiler whenever foam devel vide an automatic discharge of centrifugally separated water from steam out of an operating. 1

steam boiler.

Another object of the invention is to automatically remove from an operating boiler, the water separated from steam in a centrifugal or tangential type steam drier.

A further object of the invention is to provide an electrode operated by water separated from steam in a steam drier for effecting a discharge of said water out of the boiler.

A further object of the invention is 'toutilize water separated from steam by centrifugal force for effecting its own discharge out of an operating steam boiler.

A specific object of the invention is to provide tangential steam separators with enlarged water drains communicating with blow-off valves for discharging the drained water out of the boiler. r

A further object of the invention is to equip boilers with a pair of electrodes for effecting discharge of water separated from steam in the boiler and for blowing down the boiler when ever foam development therein reaches a dangerous level. v

Another object of the invention is to provide a process of removing water-from steam in operatin boilers wherein the removed water controls its own discharge from the boiler.

Other and further objects of the invention will become apparent to those skilled in the art from the following detailed description of the annexed sheets of drawings which disclose preferred embodiments of the invention.

On the drawings:

Figure 1 is a fragmentary side elevational view, with parts broken away and shown in vertical cross section, of a locomotive boiler equipped with a tangential steam drier and automatic blow-off devices according to this invention.

Figure 2 is a cross-sectional view, with parts in elevation, taken along the line II-II of Figure 1.

' Figure 3 is a diagrammatic plan view of the electric and air circuits accordingto this invention. 7 V

Figure 4 is an enlarged vertical cross-sectional view of the steam dome portion of the locomotive boiler and illustrating, the tangential steam drier in perspective with a portion of the drier bowl being broken away.

Figure 5 is a fragmentary side elevational view,

7 with parts broken away and shown in vertical cross section, of the steam dome portion of a locomotive boiler having a steam drier mounted therein and equipped with an electrode according to a modified embodiment of the invention. As shown on the drawings: In Figur 1, the reference numeral l0 designates generally a locomotive having the usual boiler shell H defining a boiler course l2 and plates l3 inside of the boiler shell defining a fire box M at the rear end of the boiler. The usual engineers cab I5 is mounted around the rear end of the boiler.

The boiler shell II has an opening IS in the top thereof covered with a dome ll providing the usual steam dome [8 above the top of the boiler.

A steam outlet pipe or dry pipe l9 extends upwardly into the steam dome l8 and has the open end thereof spaced beneath the top of the cover H. The dry pipe I!) is connected to a horizontal pipe l9a extending forwardly along the boiler course to the superheater equipment, operating cylinders and the like of the locomotive for supplyingsteam thereto.

A tangential steam drier is mounted on the upper end of the dry pipe l8.

As best shown in Figure 4, the tangential steam drier 20 comprises a bowl 2| having an open top 22, and an upwardly and inwardly flared bottom-23 merging into an upturned cylindrical neck portion 24 seated around the mouth of the dry pipe I9. Diametrically opposed drain outlets 25 and 26 (Fig. 2) slope downwardly from the bottom 23 at the outer periphery thereof. The neck portion 24 has an outturned downwardly sloping collar 24a around the mouth thereof and defines an outlet 24b communicating with the interior of the dry pipe A central solid disc member 21 is mounted in the bowl 2i below the top thereof, abovethe mouth 24b of the-sleeve 24 and in spaced relation from the sides of the bowl. A central supporting rod 28, holds the disc in fixed relation to the bowl. A plurality of Itangentially arranged vertically spaced vanes 29 are mounted on the disc 21 and extend upwardly therefrom against a rim 22a around the open top 22 of the bowl 2|.

As shown in Figure 4; steam entering the bowl 2| from the steam dome I8 passes through the open top 22 of the bowl and through the spaces between the vanes. 29. The vanes impart a whirling motion to the steam and cause water entrained therein to be thrown centrifugally outwardly against the side walls of the bowl 2|. The steam descends toward the bottomof the bowl in a spiral path and enters the dry pipe l9 through the opening 24b. The water being heavier than the steam, however, drains to the bottom of the bowl and can be discharged out of the drain openings 25 and 26 which slope downwardly in the direction of travel of the steam and water.

According to this invention the drain openings 25 and 26 discharge into pipes 30 and 3| respectively. The pipes 30 and 3| slope downwardly from the drier 20 toward the rear end of the boiler and are joined in a T fitting 32 with a discharge pipe 33 (Figures 1 and 5).

In the embodiment of the invention disclosed in Figure 1, the pipe 33 terminates in a T fitting 34 receiving a vertical pipe 35 depending from the top of the boiler shell H. The pipe 35 communicates with a blow-off valve 36 mounted on top of the boiler shell and serves as the inlet to the valve.

The fitting 34 also receives a horizontal pipe 31 extending rearwardly from the fitting. The pipe 31 terminates in an elbow 38 receiving a vertical pipe 39 depending from the top of the boiler shell I l.

An electrode 40 is mounted in the pipe 39 in insulated relation therefrom and extends downwardly in the pipe to a level preferably beneath 2,282,640 the drain outlets and 26 of the steam drier 20.

Water draining out of the drier bowl 2l will rise into the vertical pipe 39 into contactiwith the electrode 40 therein. As soon as the water contacts the electrode it closes an electrical circuit for opening the bloweoif valve 3650 that the water is discharged through the pipe 35 out of the boiler.

As also shown in Figure 1, a second, shorter, electrode 42 extends through the top of the boiler shell into the steam spacel2 of the boiler. This electrode is shorter than the electrode 46 but, like the electrode 40, is in insulated relation from the boiler, When foam development in the steam space l2 reaches the electrode 42 it closes an electrical circuit effecting the opening of a blow-.-ofi valve 43 communicating with the lower portion of the boiler. It should be noted that the electrode 42 is at a. level in the boiler beneath the steam dome opening I 6 so that the boiler will blow down before foam steam dome l'8.

As shown in Figures 1 and 3, the blow-oil? valves 36 and 43 are operated by air pressure from the compressed air tank 44 of the locomotive. Air from the compressed air tank 44 is directed through a pipe line 45 into branch pipes 46 and 41 entering solenoid-controlled air valves 48 and 49 respectively (Figure 3). Air from the air valve 48 is admitted to the blow-ofi valve 36 through a pipe line 50. Air from the air valve 49 is admitted to the blow-ofl? valve 43 through a pipe line 5|. A source of electric current such as a generator or battery 52 is provided. The source of electric current can be a turbo-generator driven by steam from the locomotive boiler.

The positive terminal of the battery 52 is connected through wires 53 with the insulated electrodes 40 and 42 respectively. The negative can enter the terminal of the battery 52 is connected through' wires 54 and 55 with one terminal of the solenoid in the solenoid air valves 48 and 49 respectively. The other side of the solenoid in the air valve 48 is connected through a wire 56 with alight box 5'! mounted in the engineers cab and having an indicating lamp 51a therein. The other side of the solenoid in the air valve 49 is connected through a wire 58 with another light box 59 which, if desired, can be housed in the same unit with the box 51. A light bulb 59a is mounted in the box. Wires 6!! and 6| run from the light boxes 57 and 59 to the boiler shell or the negative terminals of the electrodes 40 and 42 respectively.

When water contacts the bottom of the electrode 40 it closes an electrical circuit between the terminals of the electrode, and current will flow from the battery to actuate the solenoid in the air valve 48 for opening the valve to admit air to the air line 50. At the same time the light bulb 57a will be lit to indicate that the air valve 3 lighting of the bulb 59a and anactuation of the solenoid intheai'r valve 49 admittingair from the tank 44 through the'valve to the blow-oif valve 43, thus causing an opening of the valve. Liquid will be'blown off from the'bottom portion of the boiler through the valve 43 into a discharge line 66 also communicating with the steam separator 63. Steam will be separated and discharged'out of the opening 64 from the separator while the water will be discharged through the drainline65. T i? I v The light 51d will be lit whenever water is be-'- ing discharged out 'of the boiler fror'n'the steam drier 20, while the light 59a will be lit whenever water is being discharged from the bottom of the boiler through the blow-off valve 43; I

The device is,- therefore, entirely automatic in operation and visible means areprovided in the cab of the engine to indicate Whenever either or both the devices are discharging.

In the modification of the invention shown in Figure 5, the electrode for controlling discharge 48 is open. Air admitted through the pipe line 50 will open the blow-off valve 36 to discharge the water from the discharge pipe 33 into a pipe line 62 communicating with a steam separator 63 mounted on top of the boiler as shown in Figure 1 of the drawings. Steam flashed from the discharge water is discharged to the atmosphere through the opening 64 in the top of the steam separator while the water will drain with harmless force to the road bed through the drain line 65 communicating with the bottom of the separator.

When foam development reaches a level in the boiler high enough to contact the electrode 42,

an electrical circuit will be closed effecting a of water separated by the drier 20 is mounted in the drier bowl 2 l As shown in Figure 5, an electrode 10 is mounted in a tube H in the drier bowl and is insulated from this tube.

pipe 16 and out of the boiler in the manner described in connection with Figures 1 and 3.

Obviously the short electrode 42 and its circuit can be incorporated in the modification shown in Figure 5 or, if desired, this short electrode can be omitted 'from both modifications of the invention.

From the above description it should be under-f, stood that this inventionprovides for the positive discharge, under boiler pressure, of water sepa-'.

'wide range without departing from the principles of this invention and it is, therefore, not

the purpose to limit the patent granted hereon otherwise than necessitated by. the scope of the appended claims.

We claim as. our invention:

1. In a steam boiler having a steam drier mounted therein for separating water from steam generated by the boiler, the improvement which 4 comprises a drain line in said boiler receiving separated water from the drier, a blow-off valve mounted outside of the boiler communicating with said drain line, and electrical means mounted in said drier for opening said "blow-ofi.

valve to discharge the separated water whenever the water reaches a predetermined level in the drier,'said electrical means and said valve being.

of such design and said electrode being so'positioned that upon recession of the water level away from the electrode, the valve will close before steam reaches the valve.

2. In an operating steam boiler having a steam drier therein for separating water from the steam An electric con-' duit 12 is connected with the electrode 10 while an electrical conduit 13 is connected with the The separated water effects its own discharge and the generated by the boiler, the improvement which comprises a fluid pressure operated blow-off valve mounted on the boiler adapted to receive water only from the steam drier, an electrically controlled fluid valve for supplying operating fluid to the blow-off valve, and electrical contact means separator connected to the inlet of'the dry pipe actuated by water separated from the steam in the drier and positioned in the path of the water in advance of the blow-off valve for controlling operation of said fluid control valve, said blow-01f valve and said fluid control valve being of such design and said contact means being so positioned thatupon recession of the water level away from the contact means, the blow-off valve will close before steam reaches the same.

3. The method of discharging water separated from steam in an operating steam boiler which comprises closing an electrical circuit with said separated water whenever said water reaches a predetermined level in the boiler to open a blowoif valve for discharging said water out of the boiler under boiler pressure and opening said circuit to close the valve before steam reaches the valve. V

20 the valve.

a 4. In a boiler equipped with a steam and water and having a chamber for receiving water separated from the steam and an outlet for discharging thewater, piping connecting said outlet to a pointoutside the steam and water space of the boiler, a'normally' closed valve in said piping, electrically actuated means for opening said valve, a normally incomplete'electrical circuit including said valve operating means and an electrode so positioned as to be contacted by water upon. accumulation oi a predetermined amount thereof in said chamber for causing completion of said circuit and energization of said opening means for effecting-opening of said valve, said valve operating means beingof such design and said electrode being so positioned that upon recession of the wateraway from contact with the electrode, the valve will close before steam reaches OLAND W. CARRICK. LEWIS O. GUNDERSON. 

